This page was reviewed under our medical and editorial policy by
Frederick L. Durden, Jr, MD, Plastic and Reconstructive Surgeon & Microsurgical Reconstructive Surgeon
This page was updated on February 24, 2023.
Mucosal melanoma is a rare but aggressive disease usually diagnosed in advanced stages. Unlike most melanomas, which start in the skin, mucosal melanoma starts in the moist membranes that line the inside of the body, including the digestive tract.
All melanomas start in pigmented cells called melanocytes. Mucosal melanoma accounts for 1.4 percent of all melanomas, according to a 2018 review in Melanoma Management.
Most mucosal melanoma cases start in the lining of the head, neck, anus, vagina or vulva. Cases inside the gastrointestinal tract are less prevalent.
The disease may be called invasive if it’s spread deep into the tissue and metastatic if it’s spread to distant parts of the body, such as the liver or lungs.
Mucosal melanoma hasn’t been linked to any specific causes. Generally, older people are diagnosed, with the median age being 70. While the rate of skin melanoma cases has risen in the past 20 years, the rate of mucosal melanoma has always been fairly similar over time.
Mucosal melanoma is difficult to study because it’s so rare. So far, no risk factors have been confirmed.
Mucosal melanoma tends to occur without early symptoms. For oral mucosal melanoma, a dentist may see an ulcer or discoloration during a regular check-up. Vaginal cancer may be found during a routine Pap test. Anal cancer may be found during an anal Pap test or digital rectal exam (DRE). Mucosal melanomas are often diagnosed at advanced stages when symptoms are noticeable.
A melanoma often presents as a dark and uneven lesion in the skin or mucous membrane. But patients may experience different symptoms depending on the location of the mucosal melanoma.
Head and neck mucosal melanomas are usually nasal or oral. For these types of cancer, symptoms include:
Symptoms of vaginal cancer include:
Symptoms of anal cancer include:
Mucosal melanoma is diagnosed in the same way as skin melanoma, typically using a physical examination and a biopsy.
During a biopsy, a piece of the lesion is removed surgically and examined under a microscope for cancerous characteristics. Doctors may use a scalpel, razor or a tool called a trephine to take a small section of the suspected cancer.
After diagnosis, additional testing may be ordered to determine the stage of the cancer. Staging provides information about the severity of the disease, helping to inform the right type of treatment plan for the patient. Several staging systems are used for mucosal melanoma, depending on where it originates, but there’s no clear consensus on the staging of this disease.
Tests for staging may include:
In general, staging systems for melanoma of the skin take into account:
Though it occurs in different areas than skin melanoma, mucosal melanoma is treated in the same way. Mucosal melanoma is usually tougher to treat, however.
Common treatments include surgery, radiation therapy, immunotherapy and targeted therapy. Multiple therapies may be used as part of a comprehensive treatment plan. For example, targeted therapy and immunotherapy may be used to shrink a tumor.
Each treatment has different potential side effects and considerations. Doctors may fully explain the intended uses of any drug before the patient starts a treatment regime. The care plan constantly evolves to meet the needs of the patient, with treatments changed or reevaluated at any time.
Surgery: If the cancer is caught in earlier stages, surgery may be able to completely remove it. Surgery offers the best chances of remission, if it’s possible given the stage and location of the cancer. Even if the cancer is completely removed, it may recur later.
Radiation therapy: Radiation therapy is often used in addition to surgery to prevent cancer from recurring. It also may be used to treat locally advanced melanomas if surgery isn’t a good option. Radiation targets high-energy beams at cancer cells to kill them. It also could be used to manage symptoms of cancer, such as headaches or bone aches.
Immunotherapy: Immunotherapy drugs are given as pills or directly to the blood through an intravenous (IV) line. These medications ramp up the immune system to fight off cancer. Different immunotherapies have different side effects, such as flu-like symptoms, liver problems or weight changes.
Targeted therapy: Targeted therapies are also appropriate for treating some melanomas. These drugs are administered as pills or through an IV line. Some melanomas use specific pathways to grow, and drugs may block these pathways, preventing cancer growth. Many targeted therapies are based on specific mutations in the melanoma. For example, KIT inhibitors are used for mucosal melanomas associated with the KIT gene. Additional tests may be required to determine whether there are any mutations in the cancer’s DNA.
Clinical trials are research studies that investigate new drugs or therapies. Targeted therapy or immunotherapy drugs are always being developed and studied in trials. Patients should speak with their care team to determine whether a clinical trial is the right fit.
Chemotherapy isn’t often used as a first treatment step for melanomas, because other therapies are equally or more effective without the side effects of chemotherapy.
Palliative care is also always an option and may be added to any treatment regime. This type of treatment is meant to specifically manage the side effects and symptoms of cancer and cancer treatment.
Mucosal melanoma has a poor prognosis, and the majority of patients develop incurable metastatic disease. The survival rates are similar for all mucosal melanomas, regardless of where the cancer starts in the body.
The five-year survival rate is a measure of the percentage of patients who survive five years after their initial diagnosis. These statistics represent averages of large populations of patients and may not predict the course of the disease for any one patient.
According to the 2018 review in Melanoma Management: